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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 用函数实现求1-100之间的和
        function sum1to100() {
            let sum = 0;
            for (let i = 1; i <= 100; i++) {
                sum += i;
            }
            return sum;
        }

        document.write("1-100之间的和是：" + sum1to100());
    </script>
</body>
</html>